Publications by authors named "Kee Dong Yoon"

In this study, we aimed to determine the chemical constituents of , which led to the isolation and identification of 26 compounds. Three new prenylated dihydrobenzofurans [myrsinoic acids I (), J (), and K ()] and a new flavonoid glycoside, mearnsetin 3---L-arabinopyranoside (), were discovered, and the absolute configuration of the known compound, myrsinoic acid B (), was re-established. To ensure the structural accuracy of these compounds, comprehensive spectroscopic analyses were performed, including one- and two-dimensional nuclear magnetic resonance spectroscopy, mass spectrometry, and circular dichroism spectroscopy.

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Buch-Ham, a perennial woody vine belonging to the Piperaceae family, is traditionally used in Southeast Asia for treating various ailments such as malaria, headache, and hepatitis. This study described the isolation and identification of three new compounds, piperamides I-III (-), which belong to the maleimide-type alkaloid skeletons, along with fifteen known compounds (-) from the methanol extract of the aerial parts of . Their chemical structures were elucidated using spectroscopic methods (UV, IR, ESI-Q-TOF-MS, and 1D/2D NMR).

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(Fabaceae) has been used in traditional Indian medicine to treat a variety of ailments, including abdominal tumors. We aimed to investigate the anti-IL-6 activity of butein in ovarian cancer and elucidate the underlying molecular mechanisms. Butein was isolated and identified from flowers, and the inhibition of IL-6 signaling was investigated using the HEK-Blue™ IL-6 cell line.

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Skin aging is a major risk factor for the dermal diseases, and interventions to attenuate cellular senescence are expected to reduce the risk for age-related diseases involving skin atrophy. However, blocking cell death or extending proliferation causally results in side effects and an increased cancer risk. For identification of a safer approach, we focused on PDK1 inhibition, which could revert cellular senescence and reduce senescence factors in skin in vitro, in a human skin equivalent model and in an exploratory, placebo-controlled, interventional trial.

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In this study, high-performance countercurrent chromatography was employed to isolate six anthraquinone diglucosides, namely, cascarosides A-F, from cascara sagrada (Rhamnus purshiana DC [Rhamnaceae]) bark. The n-butanol-soluble extract of cascara sagrada was separated by off-line two-dimensional high-performance countercurrent chromatography. The first-dimensional high-performance countercurrent chromatography resolved the n-butanol-soluble extract (510 mg) of cascara sagrada using the flow-rate gradient method with a chloroform-methanol-isopropanol-water (6:6:1:4, v/v/v/v, normal-phase mode) system to afford four anthraquinone diglucoside fractions (groups I [cascarosides C-D, 71 mg], II [cascarosides E-F, 56 mg], III [cascaroside A, 53 mg], and IV [cascaroside B, 31 mg]).

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Eight kaempferol oligosaccharides were isolated and identified from Camellia japonica seed cake. The chemical structures of the isolates were determined by using chromatographic and spectroscopic techniques, such as high-performance liquid chromatography with a photodiode array detector (HPLC-PDA), one-dimensional (H and C), and two-dimensional nuclear magnetic resonance (H-H COSY, HSQC and HMBC), ESI-Q-TOF-MS, and optical rotation. To evaluate the anti-aging efficacy of kaempferol oligosaccharides for cosmetic use, the MMP-1 inhibitory effects of the isolates were studied using human dermal fibroblasts which were cultured in HaCaT cell-conditioned media.

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Background: Meyer (Araliaceae) is a highly valued medicinal plant in Asian regions, especially in Korea, China, and Japan. Chemical and biological studies on have focused primarily on its roots, whereas the seeds remain poorly understood. This study explores the phytochemical and biological properties of compounds from seeds.

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Article Synopsis
  • Superhongmi is a new rice variety developed in Korea through cross-breeding to enhance bioactive compounds, particularly targeting health benefits related to diabetes management.
  • Analysis techniques revealed that the bran extract of Superhongmi contains several beneficial compounds, including four taxifolin derivatives and cyanidin 3-glucoside, with potential anti-hyperglycemic properties.
  • Among these compounds, taxifolin showed the most significant reduction in postprandial blood glucose levels in a rat model, suggesting that these derivatives could be used in strategies to manage diabetes by inhibiting carbohydrate absorption.
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Objective: Cyanidin-3-glucoside (C3G), is a component of anthocyanin, have been considered to positively influence cognition and be beneficial for the prevention and treatment of dementia. We aimed to assess the safety and efficacy of cyanidin-3-glucoside-rich Oryza sativa L. (black rice) extract on cognitive function.

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Article Synopsis
  • Itch is a primary symptom of various skin conditions, and current treatments often fail for issues like dry skin.
  • Researchers created a botanical extract called ACTPER, which has shown promising results in alleviating itching and improving skin properties in an animal model.
  • The mechanism behind ACTPER's effectiveness is linked to its ability to increase the expression of filaggrin, a protein crucial for skin barrier function, via activation of the aryl hydrocarbon receptor (AhR) signaling pathway.
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() Ridsdale (Leeaceae) is found in tropical and subtropical countries and has historically been used as a traditional medicine in local healthcare systems. Although extracts have been found to possess anthelmintic and antioxidant-related nephroprotective and hepatoprotective effects, little attention has been paid toward the investigation of phytochemical constituents of this plant. In the current study, phytochemical analysis of isolates from led to the identification of 24 compounds, including a novel phenolic glucoside, seven triterpenoids, eight flavonoids, two phenolic glycosides, four diglycosidic compounds, and two miscellaneous compounds.

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Thirty-three phenolic compounds were identified from the extract of fermented tea (Camellia sinensis L.), including three undescribed flavonoids, namely quamoreokchaside I-II and kamoreokchaside I, along with thirty known compounds. All isolates were tested to evaluate their inhibitory effects against amyloid-beta (Aβ) aggregation through thioflavin-T (ThT) fluorescence-based assay and transmission electron microscopy (TEM).

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Introduction: Camellia japonica L. (Theaceae) is an evergreen shrub, which is cultivated as a popular ornamental tree in Korea, China, and Japan and its seeds have been used as a source of cooking oil, in cosmetics and as a traditional medicine. Intensive phytochemical works have revealed that oleanane-type saponins are the characteristic compounds of the seeds of C.

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Increasing evidence implicates changes in [Ca] and oxidative stress as causative factors in amyloid beta (Aβ)-induced neuronal cell death. Cyanidin-3-glucoside (C3G), a component of anthocyanin, has been reported to protect against glutamate-induced neuronal cell death by inhibiting Ca and Zn signaling. The present study aimed to determine whether C3G exerts a protective effect against Aβ-induced neuronal cell death in cultured rat hippocampal neurons from embryonic day 17 fetal Sprague-Dawley rats using MTT assay for cell survival, and caspase-3 assay and digital imaging methods for Ca, Zn, MMP and ROS.

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Aurea Helianthus (AH), also known as wild confederate rose or golden sunflower, is a curative herb. It has been used as a medicinal material in China due to its anti-inflammatory, immune regulatory, and anti-oxidant activities. However, its melanogenic effect on skin has not been sufficiently investigated.

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Uva-ursi leaf is widely used to treat symptoms of lower urinary tract infections. Here, we evaluated the in vitro inhibitory effects of uva-ursi extracts on 10 major human UDP-glucuronosyltransferases (UGT) isoforms. Of the 10 tested UGT isoforms, uva-ursi extracts exerted the strongest inhibitory effect on UGT1A1-mediated β-estradiol 3-glucuronidation with the lowest IC value of 8.

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(CT) is distributed through in southern regions of South Korea. Six known compounds, including three ellagitannins, one gallotannin, and two flavonoids were isolated from CT. In conclusion, the tannins, especially ellagitannins, and CT extract showed potent anti-oxidative, anti-inflammatory and anti-skin ageing activities.

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Rice is the most commonly consumed grain in the world. Black rice has been suggested to contain various bioactive compounds including anthocyanin antioxidants. There is currently little information about the nutritional benefits of black rice on brain pathology.

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In this study, the chloroform-soluble extract of Cuscuta auralis was separated successfully using off-line two-dimensional high-performance countercurrent chromatography, yielding a γ-pyrone, two alkaloids, a flavonoid, and four lignans. The first-dimensional countercurrent separation using a methylene chloride/methanol/water (11:6:5, v/v/v) system yielded three subfractions (fractions I-III). The second-dimensional countercurrent separations, conducted on fractions I-III using n-hexane/ethyl acetate/methanol/water/acetic acid (5:5:5:5:0, 3:7:3:7:0, and 1:9:1:9:0.

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Three novel butyrolactones (1-3) and butanoates (4-6), namely taraxiroside A-F, were isolated from Taraxacum officinale along with twenty-two known compounds (7-28). Their chemical structures were elucidated by interpretation of spectroscopic data and comparison with those of literatures. All isolates were evaluated for their α-glucosidase inhibitory activities.

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Ethnopharmacological Relevance: Nuclear factor-kappa B (NF-κB) plays pivotal roles in inflammation. Src and Syk are two tyrosine kinases that act upstream of NF-κB signaling. Although Achyranthes aspera L.

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Efficient high-performance countercurrent chromatography methods were developed to isolate five typical compounds from the extracts of Gentiana macrophylla. n-Butanol-soluble extract of G. macrophylla contained three hydrophilic iridoids, loganic acid (1), swertiamarin (2) and gentiopicroside (3), and a chromene derivative, macrophylloside D (4) which were successfully isolated by flow rate gradient (1.

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We evaluated in vitro, the potential of the six pairs of ginsenoside isomers, stereoisomers at the chiral carbon on position 20, to inhibit the enzymatic activity of several UDP-glucuronosyltransferase (UGT) isoenzymes, major players in the human phase II drug metabolism. The results show that the tested six pairs of ginsenoside isomers exhibited stereoselective inhibitory effects of varying degrees on the ten UGT isoenzymes explored. Of the tested twelve stereoselective ginsenosides, 20(R)-Rg3 had the strongest inhibitory effect on the UGT1A8 isoform with the lowest IC50 value of 5.

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Background And Purpose: Hepatitis C virus (HCV) infection is responsible for various chronic inflammatory liver diseases. Here, we have identified a naturally occurring compound with anti-HCV activity and have elucidated its mode of antiviral action.

Experimental Approach: Luciferase reporter and real-time RT-PCR assays were used to measure HCV replication.

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Article Synopsis
  • Researchers investigated the aerial parts of Acacia pennata from Myanmar and successfully isolated five new flavonoid glycosides along with six known compounds.
  • The new compounds were identified through detailed analysis of their spectroscopic data, revealing their complex chemical structures.
  • This study contributes to the understanding of the phytochemical properties of Acacia pennata, which may have potential applications in medicine or nutrition.
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